I have a C# WPF application that has a form with two fields. Every time the form is submitted, I want to get the values and use the Instructor class to add the new item to a list. Then, I want to loop through the list and display the items in the ListView element. I realize I can do this without the class, but having the class is a requirement for my school assignment.
Here is my Main Window class:
public partial class MainWindow : Window
    {
        private List<Instructor> instList;
        public MainWindow()
        {
            InitializeComponent();
            List<Instructor> instList = new List<Instructor> { };
        }
        private void btnCreateInstructor_Click(object sender, RoutedEventArgs e)
        {
            spCreateInstructor.Visibility = (spCreateInstructor.Visibility == Visibility.Hidden) ? Visibility.Visible : Visibility.Hidden;
        }
        private void btnInstructorSubmit_Click(object sender, RoutedEventArgs e)
        {
            instList.Add(new Instructor { firstName = txtInstructorFirstName.Text, lastName = txtInstructorLastName.Text });
            foreach (var inst in instList)
            {
                lvInstructorList.Items.Add("{0} {1}", inst.firstName, inst.lastName);  
               //Error occurs on the line above.
            }
        }
    }
This is the instructor class:
class Instructor
    {
        public string firstName { set; get; }
        public string lastName { set; get; }
    }
My problem is that I get an error saying No overload for method Add takes 3 arguments  What am I doing wrong?  I have indicated where the error occurs with a comment in the code.